*4.3. Mechanical Properties*

The mechanical properties of the hydrogel films, specifically their tensile strength (TS) and percentage elongation at break (EAB), were determined using a texture analyzer (XT plus, Stable Micro Systems, Godalming, England) following the standard ASTM D882 method [46]. For the present test, film strips that were 60 mm long and 7 mm wide were used. The equations presented below were used to determine the values of the TS and EAB for the film samples.

$$\text{TS} = \left(\frac{\text{F}}{\text{A}}\right) \tag{1}$$

F is the maximum force,

A is the cross-sectional area of the film.

$$\text{EAB} \left( \% \right) = \frac{\text{Lf} - \text{Li}}{\text{Li}} \times 100 \tag{2}$$

Lf is the final length at a break,

Li is the initial length of the film.
